Stroke is a major public health problem in the United States affecting more than 400,000 new patients annually at a cost of at least $21 billion per year. Given the impact of stroke both in monetary and human terms, it is of concern that the care of patients at risk for stroke, and those with acute stroke, is quite variable among physicians and across geographic regions. Of the many potential explanations for these variations in practice patterns, we believe that general uncertainty about how to manage patients with cerebrovascular disease is the crucial problem. Were all potential management strategies equally effective and of comparable cost, this variability would not be of special interest. Available evidence shows that this is not the case for management practices in cerebrovascular disease. We propose to examine five common strategies applied to patients with cerebrovascular disease: 1) noninvasive screening tests for carotid artery disease; 2) prophylactice use of antiplatelet agents; 3) carotid endarterectomy; 4) use of anticoagulants after stroke; and 5) hospitalization for repeat stroke. These were selected because there is significant variation in use among physicians, and their appropriate use continues to be controversial. The central element of this project is the development and application of a comprehensive model of stroke outcome. This model will serve to rationally integrate data from a variety of sources including literature data, expert opinion, claims databases, and new surveys to study physician practices and patient preferences. The stroke outcome model provides projections of the efficacy and costs of specific management practices. Evaluation of the model for a variety of patient and practice scenarios which will result in a series of specific practice recommendations. We will disseminate our findings throughout North Carolina in a form appropriate to the needs of practicing physicians. Based on previous research, we believe that when physicians are informed of the likely impact of these strategies on their own patients, they will voluntarily modify their practices to favor more effective and more cost-effective strategies.